polysorbates

Polysorbates are a class of nonionic emulsifiers derived from sorbitan and fatty acids, produced by esterifying sorbitan with a fatty acid and then ethoxylating the molecule to introduce polyoxyethylene chains. They are designated as polysorbate X (for example polysorbate 20, 60, 80), where the X typically corresponds to the fatty acid moiety: Tween 20 is polyoxyethylene sorbitan monolaurate, Tween 60 is polyoxyethylene sorbitan monostearate, and Tween 80 is polyoxyethylene sorbitan monooleate. Their hydrophilic-lipophilic balance (HLB) values generally span from about 8 to 16, making them suitable for stabilizing a range of oil-in-water emulsions.

Common uses include food, cosmetics, and pharmaceuticals. In foods, polysorbates act as emulsifiers to improve texture and prevent phase separation in products like ice cream, dressings, and baked goods. In cosmetics and personal care, they function as emulsifiers, surfactants, and solubilizers in creams, lotions, shampoos, and cleansers. In pharmaceuticals, they aid in solubilizing poorly soluble drugs, stabilizing suspensions, and improving palatability of liquid formulations.

Regulatory and safety notes: polysorbates are widely used and generally recognized as safe for specified uses in foods, cosmetics, and medicines. They are nonionic and typically well tolerated, though rare hypersensitivity reactions can occur in some individuals. They can hydrolyze under extreme pH conditions or high temperatures, and storage should be in tightly closed containers protected from light and heat to minimize degradation and oxidation.